react/require-render-return shouldn't warn if render is defined using (stage 1) class property syntax

[jimbolla]

react/require-render-return will error if a class is defined with this syntax:

export default class UserList extends React.Component {
  render = () => (
    <div/>
  );
}

We use this syntax to make our class function declarations consistent between render and event handler functions.

http://babeljs.io/docs/plugins/transform-class-properties/

[ljharb]

Instance properties are not yet standard - and doing this (instead of render() {) is actually much slower, and I think is something that should be discouraged.

[billyjanitsch]

@ljharb why would it be much slower? Doesn't React already bind all standard component methods to the instance in the constructor anyway?

[ljharb]

@billyjanitsch only in React.createClass, not in class-based components.

[ljharb]

@yannickcr this change is breaking something in eslint-config-airbnb

Cannot read property 'name' of undefined
TypeError: Cannot read property 'name' of undefined
    at getPropertyName ($PROJECT/node_modules/eslint-plugin-react/lib/rules/require-render-return.js:54:20)
    at Object.ArrowFunctionExpression ($PROJECT/node_modules/eslint-plugin-react/lib/rules/require-render-return.js:93:40)
    at EventEmitter.updatedRuleInstructions.(anonymous function) ($PROJECT/node_modules/eslint-plugin-react/lib/util/Components.js:457:75)
    at emitOne (events.js:101:20)
    at EventEmitter.emit (events.js:188:7)
    at NodeEventGenerator.enterNode ($PROJECT/node_modules/eslint/lib/util/node-event-generator.js:40:22)
    at CodePathAnalyzer.enterNode ($PROJECT/node_modules/eslint/lib/code-path-analysis/code-path-analynpm ERR! Test failed.  See above for more details.

[yannickcr]

@ljharb Ho. Do you know what code makes it crash ?

[vdh]

@yannickcr It looks similar to this issue in eslint-plugin-import: import-js/eslint-plugin-import#317

[ljharb]

I'm afraid I don't - it doesn't tell me which.

[ljharb]

fwiw I'm not using any proposed ES syntax.

[yannickcr]

Ok, the following pattern trigger the crash:

var Hello = () => (
  <div></div>
);

I'll do a quick fix.